Hyperbaric chamber



United States Patent [72] Inventors Lester P. Kolman Madison; Harold L. May, Oregon; Richard C. Berry, Madison, Wis. [21] Appl. No. 643,141 [22] Filed June 2,1967 [45] Patented Dec. 15, 1970 [73] Assignee Air Reduction Company, Incorporated New York, N.Y. a corporation of New York [54] HYPERBARIC CHAMBER 11 Claims, 4 Drawing Figs.

[52] 11.8. CI 128/204, 128/ 142.2 [51] Int. Cl A6lm 16/02 [50] Field ofSearch 128/142, 142.2, 204, 142.5; 137/63, 64, (Digest); 98/15 [56] References Cited UNITED STATES PATENTS 2,834,343 3/1958 Keckley et al. l28/142.5 3,190,287 6/1965 Miller, Jr. 128/142.5 3,348,538 10/1967 Benzel 128/142 ArtorneysFrancis B. Henry, Edmund W. Bopp and H. Hume Mathews ABSTRACT: Normally sealed chamber for accommodating therein a person or persons which has an environmental atmosphere that may be maintained at any selected hyperbaric pressure. A supplemental service system within the chamber includes regulators, piping and valves for separate distribution of oxygen to personnel face masks. The service gas supply is derived from a high-pressure pressure source apart from the chamber through pressure regulator and back-pressure relief devices subject to chamber pressure, which maintain the service line pressure at a constant predetermined pressure differential with respect to chamber pressure. A breathing demand regulator receives the regulated oxygen supply for facilitating breathing at individual face masks.

For medical purposes, such as removing fluids, etc. from the chamber, a negative pressure(vacuum) service system includes a regulator responsive to the chamber pressure and valved to a lower reference pressure level exteriorly of the chamber for maintaining at the regulator inlet a constant vacuum differential in the service line.

38 TO ATMOSPHERE PATENTED um 5|97fl 3.647118 SHEET 1 OF 2 To ATMOSPHERE LESTER P. koLMA/v" INVENTORS HAROLD L.MAY

By RICHARD c. BERRY ATTORNEY HYPERBARIC CHAMBER This invention relates to environmental chambers, such as hyperbaric chambers within which medical, research and other personnel can work in an isolated, pressurized atmosphere, and in particular to environmental chambers of this type wherein a supplemental supply of oxygen, medical service gas or the like is separately provided for the use of personnel within the chamber.

Following the basic principle of the diving bell" as used by construction engineers for many years, pressure chambers have more recently come into increasing use, such as by hospitals for hyperbaric therapy, and scientific groups for deep sea exploration and research. In these typical applications of the hyperbaric chamber, oxygen is generally made available in addition to the pressurized atmosphere of the chamber, for use in face masks or the like, according for example, to the needs of a patient undergoing therapy, standby emergency in deep sea chambers, breathing requirements in relation to the composition of the pressurized chamber atmosphere, etc.

Insofar as presently known, the supplemental oxygen supply for hyperbaric chambers was prior to this invention controlled by manual adjustment, or supplied at some reference pressure not directly related to possible variations in the environmental chamber pressure. Accordingly, as the chamber pressure varied, the oxygen supply to the face mask also tended to vary, absent continuous and immediate precise compensating adjustment of the oxygen supply. The disadvantages of imprecise oxygen supply control incident to chamber pressure transients tending temporarily to vary oxygen supply to the mask will be apparent.

A principal object of this invention, therefore, is to provide an environmental or hyperbaric chambers an improved control system for supplying a supplemental service gas such as oxygen, that automatically compensates for varying chamber pressure by so adjusting the service gas supply pressure that it is maintained at a constant pressure differential .with reference to the chamber pressure.

A further object of the invention is to provide an improved combination including the service gas pressure control and a face mask breathing, demand regulator for facilitating breathing of personnel.

A further object of the invention is to provide in a hyperbaric chamber system, a supplemental service gas control system which will allow low pressure, inexpensive breathing demand regulator and associated equipment to be used.

In accordance with the invention in a disclosed form thereof, the service gas or oxygen system includes a pressure regulator and relief valve combination located within the hyperbaric chamber and subject to chamber pressure, that receives oxygen from a high pressure source outside the chamber at a pressure higher than that of the chamber; the regulator is adjusted for a predetermined differential pressure output for the oxygen supply line with respect to the chamber pressure so that the oxygen line is maintained at this differential pressure coincident with increase in chamber pressure above a reference level, and the pressure-relief valve functions upon decrease of the chamber pressure below the reference value as a back pressure regulator to vent excess supply pressure at the regulator outlet and restore the supply pressure to the predetermined differential value. This constant differential pressure of the oxygen in the service line lends itself to uniform operation of a breathing demand regulator that admits oxygen to a face mask, so that less breathing effort at the mask is required.

The invention will more fully set forth in the following description referring to the accompanying drawings, and the features of novelty will be pointed out with particularity in the claims annexed to and forming a part of this specification.

Referring specifically to the drawings:

FIG. 1 is a partly schematic plan view of a hyperbaric chamber having a supplemental gas supply system embodying the invention;

FIG. 2 is an elevational view, mainly in section, of the principal components of the supplemental gas system indicated generally in FIG. 1; 7

FIG. 3 is an elevational view in section of a differential low pressure regulator for maintaining a differential negative pressure on a service line in the hyperbaric chamber; and

FIG. 4 is a pressure chart illustrating control functions of the invention.

A hyperbaric chamber installation of the general type used by hospitals for therapy is schematically indicated in H0. 1. The chamber is formed by a strong metal tank HC adapted to be hermetically sealed for containing an environmental atmosphere at selected hyperbaric pressure, and is of sufficient size to accommodate a team of operating personnel. As disclosed herein, the chamber HC is used for surgical cases and contains appropriate medical equipment including an operating table T and face mask equipment FM connected in suitable manner to an oxygen supplyline SL, the pressure of which is controlled as described later. The environmental atmosphere of the chamber here is air maintained at a hyperbaric pressure, say 50 p.s.i., by a high pressure source, such as a centrifugal pump CP that is connected to the chamber through a conventional output pressure regulator R.

Entrance to the chamber can be made in usual manner through pressure locks generally indicated at PL that in turn may communicate with other hyperbaric chambers for diag nostic and therapeutic purposes respectively, thereby forming an integrated multiple-chamber medical complex.

The regulating system which will be described in detail below may be used with large chambers as shown in FIG. 1 or with small chambers designed to accommodate an individual patient or person. The system may also be used with hyperbaric chambers adapted for underwater research.

The supplemental service gas, herein oxygen, is supplied through a separate system within the chamber including the oxygen supply line SL that extends generally around the inside chamber wall according to the location requirements of supply outlets S0. The oxygen pressure in the supply line SL is regulated with respect to the chamber hyperbaric pressure through a differential pressure regulatingsystem DP, FIGS. 1 and 2, that is in turn connected as indicated through conventional control components including flow limiting and check valves, V and V respectively, and pressure regulator R to a high-pressure source of oxygen 0 located exteriorly of the chamber. A safety factor is provided by the flow limiting valve V in case of failure, diaphragm rupture, etc. in the pressure regulating system. Flow limiting valves are well known in the art and need not be described in detail. The source 0 is maintained at a pressure, for example 1000 p.s.i., that is higher than the hyperbaric chamber pressure. The system DP may be located within the chamber, as shown, in contrast to the exterior location of the high pressure source 0, and is subject to the hyperbaric pressure of the chamber for purposes of differential control.

Referring to the differential pressure control system DP as shown more specifically in FIG. 2, a main regulator 10 is connected to the oxygen source through a high pressure line 11 extending through the chamber wall. The main regulator may be of the so-called indirecttype and comprises a pressure sensitive diaphragm 12 that partitions the regulator housing into an upper compartment 13, having direct communication at vents 13,, with the pressurized chamber air, and a lower compartment 14 having inlet and outlet ports 15 and 16, respectively. The inlet port is controlled by a regulating valve 17 adapted to seat at 17a according, as presently described, to the selected differential adjustment of the regulator for ad mitting high pressure oxygen from the line ll through the regulator inlet passages 11a and 11b respectively, to the regulator compartment 14.

The differential adjustment includes an adjusting spring 18 located within the upper compartment 13 and seating at one end on the diaphragm 12 at 19, and at the opposite end on a positioning disc 20 that is adjustable at 21 for varying the spring tension (in compression) and hence bias on the diaphragm. The diaphragm spring seat at 19is in turn directly connected at 22 to the valve 17, so that the bias of the main spring 18 tends to open the valve. The valve is also biased by a marginal spring23'within the inlet passage llb. When the pressure in passage 11b balances the pressure in compartment 1-33plus thespring force 18, the marginal spring assists in fully seating thevalve 17.

he compartment 14' is the service line source of the regulated service oxygen supply and communicates directly at the,

outlet port'l6 with a so-called back -pressure regulator 25 through a line 26, and with the service line SL, FIGS. 1 and, 2, through a service isolating valve 27 or the like. The back pressure regulator may be. of the directtype as compared with tlij'regulator '10 above, and comprises a pressure sensitive diaphragm 27 that partitions the regulator housing into upper lower compartments 28 and, 29, respectively. The upper lcor'npartment is vented to the hyperbaric chamber at 28a and ntains an adjusting spring 30 positioned in compression between a seat 31 on the diaphragm andan adjustable disc seat 32. An adjusting screw at 33 can vary the spring force to correspond with the adjustment of the main spring 18 of regulator 10.

The lower compartment 29.0f the back pressure regulator is as'load of the environmental chamber. Opening of the valve in esponse to unbalance of the forces acting on the diaphragm vents excess pressure in the main regulator comrtment 14 to normal atmosphere until the opposing pressures at the diaphragm 27 are balanced.

The system DP could be located outside the'chamber if the chamber pressure were bled through conduits to the appropriate sides of the diaphragms in the regulators 10 and 25. Thus the regulators would sense. chamber pressure for purposes of control but would be remote from the chamber. In this .type of construction the service lineSL would of course lead into the chamber.

' The regulators 10 and 25 have been described as of the indirect" and fdire ct" type respectively. This'is meant as an illustration only since any regulator either direct or indirect which can perform the desired function can be utilized.

' It has been found advantageous to provide the system with high pressure safety valves in the supply line in order to insure thatthe supply line does not collapse.=due to an increase in .c-l ramber pressure. For example, if the source were shut off,

the]valvevclosedand the chamber pressure increased, the supply line between the valve V and DP might collapse. By

placing a spring loaded valve S in communication with the line ERATlON or DIFFERENTIAL POSITIVE-PRESSURE OXYGEN SYSTEM he pressure-regulating. equipment described above supoxygen as neededto the line SL'at a constant differential pressure with respect to that of the hyperbaric chamber pressure-P ssuming that the differential selected is 60 p.s.i. for exam- .the oxygen supply pressure inv the line SL will vary as Fe via es, maintaining however a constant differential of 60 p.s.i. .o' r Pc. To this end, the spring 18 of the main regulator is ted in relation to the opposing force of-the oxygen presm-chamber ldrqfor a -resultant bias representingO p.s.i.

compartment air pressure Pc, also acting in thesame direction as the spring 18 on diaphragm 12.

Accordingly, when oxygen supply demand on the line SL tends to lower the supply pressure Ps in the regulator control compartment 14, thereby unbalancing the diaphragm forces, the chamber pressure Po and the main biasing spring 18 jointly depress the diaphragm and open the valve 17 to admit oxygen at higher pressuretothe compartment 14. When the supply pressure has been'so restored to its normal differential over P,, the valve closes under bias of its restoring spring 23 until further oxygen demand reduces the pressure in compartment 14 and causes repetition of the regulating cycle.

The cycle described above occurs when thechamber pressure Pc remains either at the selected hyperbaric level or increases somewhat above it. In the latter instance, it will be apparent that due to the increased bias of Pc on the diaphragm '12, the valve 17 will open sufficiently for the oxygen supply pressure P, in compartment 14 to increase and match in amount the increase in Pc, thereby restoring the p.s.i. differential. In brief, it cannot lower the pressure P, with respect to P 'as the valve 17 admits only oxygen at a pressure materially higher than Pc to the regulator. Accordingly, the pressure differential tends to be greater than 60 p.s.i. and can be restored only when Ps is reduced to match the decrease in P0.

The differential restoring function when Pc so decreases is performed by the back pressure regulator 25; As Pc decreases, the excess pressure P, in the regulator compartment 14 acting on the diaphragm 12, tends to hold the valve 17 closed. This pressure also acts through line 26 on the diaphragm 27 of the back pressure regulator 25, likewise subject to Pc. Accordingly, the diaphragm is deflected sufficiently .to open the valve 37 and vent the; compartment 29, and hence the main regulator compartment 14, to atmosphere through exhaust line 38 fordecreasing Ps until the normal differential is again restored. The biasing spring 30 thereupon closes the exhaust valve 37. This regulating cycle for maintaining the differential is repeated as long as P is decreasing.

Reference is made to FIG. 4 for diagrammatically showing the essential control functions of the system DP for maintaining a constant pressure differential pd of the supply line pressure over the hyperbaric chamber pressure Pc, coincident with possible variations of Pc.

As described above, where Pc remainsconstant, i.e. at a selected pressure P or rises above P to a value P the regulator 10 functions to maintain the constant differential pressure dp by opening its valve 17 to an extent bringing the oxygen supply pressure up to the value P,, If on the other hand, Pc should drop below P to a value P the supply line pressure P is lowered to a value P by venting the excess supply pressure at the relief valve 37 of the back pressure control 25 until the pressure differential pd is restored. It will therefore be. apparent that notwithstanding variations in the chamber pressure P0 with respect to P the difference between Fe and. P5 tends to constant. This difference dp can be set by appropriate adjustment as described above, into the.

pressure control system DP at a value that is relatively small with referenceto the hyperbaric chamber pressure, so that in practice the 'sypply line can use standard, comparatively in.-

expensive low-pressure: control components and fittings, as compared with specially designed equipment ordinarily.-

epair r for E iPEEEEEZQEFFlbllllQEllPE?- forms no part of this invention and therefore is not described in detail. Reference maybe had to [1.8. Pat. No. 2,693,178 for. a description of a demand-type gas regulator using, a,v

mechanism for automatically actuating a'demand valve in 13C could be used as indicated at 40, FIG. 1, in combination with the control system herein disclosed.

It will be apparent therefore, that the regulated oxygen supply provided by this invention advantageously lends itself to a breathing demand regulator as the oxygen is supplied to the mask evenly and uniformly, irrespective of-variations in the hyperbaric chamber pressure, thereby greatly facilitating use of the oxygen supply by the patient and other personnel.

The regulated supply may also be used as an input to a flowmetermask, anesthetic machine or other therapeutic device as may be utilized in such chambers.

While reference has been made to an oxygen supply, it is understood that the invention may be used to regulate the supply of a mixture of oxygen and other gases such as nitrogen or helium or, in fact, any gas supply that is needed in the chamber.

The gas that is supplied through the pressure-regulating system described in detail above may be the same as that supplied through the high pressure source CP or it may differ therefrom. This would depend on the requirements to be met in the chamber. For example the high pressure source could supply air, or oxygen enriched air and source 0 could supply oxygen.

Generally in chambers using the subject-regulation system, the chamber pressure is adjustable by varying the high pressure input CF to create the desired atmosphere in the chamber. When a different chamber pressure is desired it is altered and the subject-regulation system automatically compensates.

OPERATION OF DIFFERENTIAL NEGATIVE-PRESSURE SERVICE LINE SYSTEM between the vacuum in a service line and a hyperbaric chamber pressure.

A simple and efficient control regulator system for this purpose is shown by FIG. 3 wherein a regulator housing unit 60 has a pressure sensitive diaphragm 61 that partitions the housing into upper and lower compartments 62 and 73. The compartment 63 is open to the chamber pressure Pc at vent 63a, and the compartment 62 at port 64 is connected to. a vacuum service line VL in the chamber HC through an isolating valve 65, and also at a valve controlled passage 66 to a low pressure line 67 leading through the chamber wall as indicated to a vacuum pump, or atmosphere as the case may be, depending on the magnitude of P For controlling the low pressure passage 66, a valve 68 connected directly to the diaphragm 61 is biased toward open position by, a spring 69 that seats between the diaphragm and a ring 70 that is positioned by adjusting screws 71 for varying the spring pressure according to the desired pressure differential.

Assuming that Fe is well in excess of atmospheric pressure, opening of the valve 65 starts flow of air into the vacuum service line at the active suction outlets from the chamber I-IC. As the pressure in compartment 62 increases toward the value of Pc, the differential spring 69 acting jointly with this pressure depresses the diaphragm, causing the valve 68 to open and vent the compartment (and the line VL), to a lower pressure level. This establishes a steady flow or drain of air from the chamber through the line VL and regulator so that suction occurs at the active service connections of the vacuum line. Where the chamber pressure is not materially above atmospheric pressure, a vacuum pump may be used as the low pressure reference level for establishing sufficiently strong suction action. The vacuum pump may be automatically cut in at a low chamber pressure level by means of a pressure operated switch dependent on chamber pressure. Thus, suction force is assured even when the chamber pressure is lowered to slightly above atmospheric.

The regulator system for creating a suction pressure could also be located outside the chamber if the chamber pressure Pc were transmitted to the appropriate side of the diaphragm and the vacuum line we're connected to the other side. The particular regulatorshown in FIG. 3 is merely illustrative of one type of regulator that would perform the desired function. In order to protect the vacuum line from collapsing it has been found advantageous to place a safety valve in the vacuum line. Thus, if the valve 65 were in the closed position and the chamber pressure were increased the vacuum line between 65 and regulator 60 might collapse. By placing this line in communication with the output of an adjustable spring loaded valve S, which would be urged open by the increase in pressure, the line would be prevented from collapsing. This valve S which may be described as a safety valve makes it possible to use standard parts in the vacuum line in that they are not subject to high differential pressure and it also avoids high vacuum when the vacuum connection is first used.

The vacuum pressure created by regulator 60 may be used for any desired purpose in the chamber. For example, it may be used to collect material in the chamber or transmit the material outside the chamber.

It should be understood that this invention is not limited to specific details of construction and arrangement thereof herein illustrated, and that changes and modifications may occur to one skilled in the art without departing from the spirit of the invention. For example, the invention is readily applicable to hyperbaric chambers for underwater research, etc. such as those having onshore (or ship) supply facilities, as the character of the chamber ambient is not necessarily determining; in such cases the low pressure exhaust lines extending from the immersed chamber would of course, vent at some point above water level.

We claim:

1. A chamber having an atmosphere under a predetermined hyperbaric pressure, a supply line within the chamber for conducting gas between upper and lower pressure levels, means for connecting the line to chamber service equipment, control means for regulating the pressure of gas in the supply line comprising valve means, and means controlling said valve means responsive to variations in the hyperbaric chamber pressure for maintaining the gas pressure in said line at the service connecting means at a constant differential pressure with respect to and materially different from the chamber pressure, said controlling means including means responsive to a decrease in chamber pressure to vent the supply line pressure so as to maintain the said constant differential pressure between the supply line and the chamber.

2. A chamber apparatus as specified in claim I wherein the controlling means includes a pressure sensitive diaphragm communicating at one side with the supply line pressure and at the other side with the hyperbaric chamber pressure acting on the diaphragm in the opposite direction.

3. A chamber apparatus as specified in claim 2 wherein an adjustable biasing spring acts on the diaphragm in a direction for establishing a pressure differential in the line with respect to hyperbaric chamber pressure. v

4. A chamber as specified in claim 1 further comprising means to supply oxygen to the supply line.

5. In an environmental chamber containing an atmosphere under a selected hyperbaric pressure, supply means for delivering a supplemental service gas to the chamber comprising:

a. a high pressure source of service gas;

b. a service gas supply line having service outlet means within the chamber;

c. and control means connected to the high pressure source for delivering to the supply line service gas at regulated pressure, said control means maintaining a constant difference between the pressure of the service gas in the supply line and the hyperbaric pressure of the chamber, said control means including means to vent the supply line gas pressure in response to a decrease in the chamber pressure so as to maintain the said constant difference between the supply line pressure and the chamber pres sure, said control means further including means to adjustably set the difference between the supply line pressure and the chamber pressure.

6. In an environmental chamber containing an atmosphere that is maintained at a selected hyperbaric referencepressure, supply means for delivering a supplemental service gas to the "chamber comprising:

a. a high pressure source of service gas;

b. a gas supply line having service outlet means within the chamber;

c. differential pressure regulating means connected to the source delivering gas to the supply line at a constant differential pressure above the chamber pressure in response to cyclic variations of the chamber pressure above the hyperbaric reference pressure;

d. and means responsive to cyclic variations of chamber pressure below the hyperbaric reference pressure for venting the supply line exteriorily of the chamber for maintaining the supply line pressure at said constant differential over the chamber pressure.

In achamber as defined in claim d. a vacuum line for creating a suction pressure in said chamber;

e. and second control means in said vacuum line for maintaining a low pressure in said vacuum line compared with said chamber pressure.

8. In a method of operating a chamber having an atmosphere that is maintained at a hyperbaric reference pressure subject to variations, and containing a supplemental lifesustaining gas supply system for breathing equipment within the chamber, the method which consists of admitting the gas from a high pressure source to the chamber supply system at a pressure that is materially higher than the chamber reference pressure, adjusting the supply pressure as applied to the breathing equipment for maintaining a constant positive differential of the supply pressure over the chamber pressure coincidentwith variation of chamber pressure, wherein adjustmentofthe supply pressure includes admitting gas from the high pressure source for increasing the supply pressure by an amount equal to an increase in chamber pressure above the reference pressure, and reducing the supply pressure in amount equal to a decrease in chamber pressure below the reference pressure by venting the excess supply pressure to a comparatively low pressure level exteriorly of the chamber.

9. In a chamber as defined in claim 6, safety valve means in said supply line for venting chamber pressure into said supply line so as to prevent collapse of said supply line.

10. A hyperbaric chamber containing an atmosphere under hyperbaric pressure, a suction line having an intake in said chamber, regulator means responsive to the pressure in said chamber for creating a lower pressure in said suction line than in said chamber, said regulator means comprising diaphragm means having one side communicating with chamber pressure, the other side of said diaphragm means communicating with said suction line, spring means loading said diaphragm means in opposition to said chamber pressure, and valve means in said suction line connected to said diaphragm means to control the flow through said line.

11. in a chamber as defined in claim 10, a safety valve means in said suction line for venting chamber pressure into said line so as to prevent collapse of said suction line.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,5 7, Dated December 15, 1970 Inventor) Lester P. Kolman, Harold L. May and Richard C. Ber

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 3, after line 7 the following has been omitted,

"on the diagram 12. This bias is superposed on the up Col. 4, line 20, after "ferential" the following is missing --If on the other hand, P should decrease below the selected hyperbaric value, the main regulator 10 by itself is ineffective for restoring the 60 p.s.i. differential.-

Col. t, after line 7A, the following line is missing:

-- cordance with a breathing cycle. A comparable mechanism.

Signed and sealed this 6th day of July 1971.

(SEAL) Attest:

EDWARD M.FLETCHER JR. WILLIAM E. SCHUILER, JR. Attesting Officer Commissioner of Patents 

